Need carburators. Performance upgraded '75 455 motor

[Bassem ABOU ANTOUN]

I have a '75 engine upgraded for street performance.*
TA stage 1 heads.
TA camshaft*
Forged pistons
Offenhausser dual quad intake
Mallory ignition
New oil pump
New fuel pump
Still waiting for double roller chain and aluminum water pump cover and new water pump.*
I want now to choose my carburators. I need 2 carburators for the dual quad, for street performance and drag racing.
Which carburators do you suggest? And how many cfm each one should be? Manual or electric choke is better?

[carmantx]

I have built quadrajets for the dual intake. I used Buick units converted to electric choke.
I think some of those intakes were set up for AFB carbs. Could use the Edelbrock carb since they are the old AFB design. I'm not a fan of those, but lots of them out there.

[Bassem ABOU ANTOUN]

I have built quadrajets for the dual intake. I used Buick units converted to electric choke.
I think some of those intakes were set up for AFB carbs. Could use the Edelbrock carb since they are the old AFB design. I'm not a fan of those, but lots of them out there.

What do you think of 2 holleys xp 500 cfm electric choke each for the dual quad?

[Dr. Frankenbuick]

I think you want to go bigger. The 401s and 425s had two 625 CFM carbs as part of the stock package. I have been told they made more power with 700+ CFM carbs.


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[Bassem ABOU ANTOUN]

I think you want to go bigger. The 401s and 425s had two 625 CFM carbs as part of the stock package. I have been told they made more power with 700+ CFM carbs.


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So do you think dual holley 750 cfm double pumper are a good choice?

[bob k. mando]

doesn't TA have a recommendation?

[Bob]

You have to decide how high you expect the motor to rev. Then you can use a calculator to assess minimum air requirements:
http://www.teambuick.com/reference/c...calculator.php

Personally I find the minimum requirement quite low for performance and would recommend an increase of up to about 50% for performance. I think most people would find it easier to work with vacuum secondary carburetors in a dual carb street application and there would be good reasons to suggest spread bore designs for higher cfm choices.